What's the best way to say you're in training before a match?

Question

What's the best way to say you're in training before a match? Can I simply use 'in training' or would 'at practice' sound better? Also, as I mean to use these words as nouns, should i put an article before them- a/an/the? And if not, then why? Example:

1. She's not at home, she's in training before a big match next week.
2. She's not at home, she's in A training before a big match next week.
3. She's not at home, she's at practice before a big match next week.
4. She's not at home, she's at A practice before a big match next week.

Also, are the prepositions 'AT practice' and 'IN training' correct here?

And could I also use for in the place of 'before' in either one of these sentences? E:

1. She's in training for a big match next week.
2. She's at practice for a big match next week

Also, do we NOT use articles before either training or practice? For example, if I wanted to say:

1. That was A good training/practice. OR
2. That was good training/practice.

Which one would be correct? As both practice and training are nouns in above sentences there should be an article before each but I've seen both used without one.

Answer 1

The article 'a' or 'the' makes the noun a count noun, which is used to differentiate discrete examples of the noun (which would make them countable) from uncountable uses such as indicating the concept which the noun names.

Examining the prepositional phrases:

In is used here to indicate a state of being by way of being inside a (mass noun used to indicate a) concept. Similar uses of in include in mourning, in thought, and others.

Thus, in this instance in a training is both awkward and incorrect because it conveys that she is inside a training. You might ask yourself, what is one training, and how does it contain a person?

At, on the other hand, is a bit more complex. At practice is common usage, but is used to indicate the physical place at which a person is located. She's at a practice is correct, although sounds awkward because it's unusual not to have a specific, single practice in mind when you tell someone her location. "She's at the practice" sounds less awkward and conveys the same thing. If, however, there are 4 practices being conducted at different places and you don't know which one she's at, she's at a practice is correct to use.

Now, why 'she's at practice' is common usage is a difficult concept. At can be used with a concept to convey a state of being, such as with "at work" or "at play". Here, however, it is meant to convey physical location. One of the things English tends to do is construct nominal phrases- phrases that collectively stand in place of a single noun. It's likely a shortening of something like "at swim practice" where swim practice is a concept with a discrete location and time that the speaker assumes the listener understands through shared context. Not correct usage, but actual usage.